I mean easy enough to recreate it with a more open database, but yeah key issue is userbase. Same flaw with trying to make a better dating site, or anything else location specific. It's barely feasible for things like lemmy and mastadon where we pull from international pools of people that mostly don't care if the other users are 500 miles away.

When you try to do a facebook equivelant, doesn't really go anywhere because, people don't need just people, but people they actually know.

and yeah trying to get "people in the same city".

as obviously one guy just reporting the gas stations around him, for an application that only he uses, is just a fancy notebook, and the real problem is would he continue using it long enough for a second to appear and make it actually beneficial for anyone.